Signaling system



Dec. 3, 194-0.

H. J. GRAHAM SIGNALING SYSTEM 9', 1957 4 Sheets-Sheet 1 Filed Dec.

llll I l-llu Dec, 3, 1940. 1-1. J. GRAHAM SIGNALING SYSTEM Filed Dec. 9, 1937 4 Sheets-Sheet 2 [wen i32 HmZd Jaraiaazaw, yaw-M v WW Dec. 3, 1940. H. J. GRAHAM SIGNALING SYSTEM 4 Sheets-Sheet 3 Hamzd warm Filed Dec. 9, 1937 Dec. 35 19%.

H. .1. GRAHAM 2,223,868

S IGNALING SYSTEM Filed Dec. 9; 193? 4 Sheets-Sheet 4 Patented Dec. 3, 1940 UNITED STATES SIGNALING SYSTEM Harold J. Graham, Boston, Mass, assignor, by

mesne assignments, to Signaling Systems Incorporated, Winthrop, Mass, a corporation of Massachusetts Application December 9, 1937, Serial No. 178,941

15 Claims.

My invention relates to signaling systems, particularly but not exclusively to those in which a signal is given at a station in response to a condition at ony one of a plurality of remote stations,

such a system being exemplified, for example, by a fire alarm system for a ship or the like in which the existence of a fire in any particular one of a number of staterooms is signaled at the bridge, or any other convenient station on the ship, by use of a bell which taps the number of the stateroom at such station.

The invention will be best understood from the following description when read in the light of the accompanying drawings, the scope of the invention being more particularly pointed out in the appended claims.

In the drawings Fig. l is a schematic diagram of an alarm system according to the invention;

Fig. 2 is a plan of a selective switch and associated mechanism employed in the system according to Fig. 1;

Fig. 3 is an elevation of the parts shown by Fig. 2;

Fig. 4 is a section on the line 4-4 of Fig. 2 on an enlarged scale, with parts omitted, parts broken away, and parts moved to a different position;

Fig. 5 is a plan of the parts illustrated by Fig. 4; and

Fig. 6 illustrates a detail.

Referring to the drawings, the alarm system comprises a panel 11, indicated by dotted lines in Fig. 1, which panel is located, for example, at the bridge of theship and supports a single stroke bell l3 for tapping off the numbers of staterooms or other places on the ship when a fire or other condition to be signalled occurs at any one of such places. For causing the bell to be actuated there is located in each of these places a thermostatically or otherwise controlled device which responds to heat or other condition to cause the bell to be operated.

As illustrated in Fig. l, for controlling the bell circuit there is provided a switch having a spring contact arm 11 and a cooperating spring contact arm 18. By reference to Fig. 1 it will be observed that when the contact arm 11 is moved into contact with the arm l9 there will be established across the battery 2|, if the battery switch 23 is closed, which it normally is, a circuit through the winding of the relay 25 by way of the leads 21, 29, 3|, 33, and 31. This circuit being established, the armature 39 of therelay will be drawn downward against the tension of the spring 4| to close the relay switch 43, and that switch being closed will establish a circuit through the bell 13 from the battery by way of the leads 21, 45, 41, 35 and 31. When the relay 25 is deenergized by opening of the switch 11, I9 the spring 41 will open the switch 43 to interrupt the circuit through the bell l3. This bell is of the so-called single stroke type, that is to say, when energized the bell sounds a single stroke, instead of ringing continuously. Therefore it will be observed that by causing the switch l1, l9 successively to open and close in definite timed relation between each opening and closing thereof the bell 13 may be caused to tap off numbers or other signals. It will of course be understood by those skilled in the art that other signaling means, for example, a lamp caused to flash by opening and closing of the switch aiforded by the contacts l1 and 19, may be substituted for the bell I3, or the bell and such a lamp may be arranged in parallel across the leads 35 and 41 so that they will operate simultaneously.

Referring to Fig. 1, the switch l1, l9, as will hereinafter be more fully explained, is caused to be opened and closed by a rotary member 49 driven by an electric motor 51, the rotary member being mounted on a slowly rotating shaft 53 driven by the motor. This rotary member 49 is shown as provided with a series of pins or other projections 55, 51, 59, which pins, as shown by Fig. 4, are arrangedin different planes respectively. Each device I5 when operated causes selective switch elements 6| (Figs. 2 and 3), one of which is indicated schematically in Fig. l, to be arranged in the planes of the respective pins in the space between the rotary member 49 and the switch l1, l9. When the motor 5| is placed in operation to rotate the member 49, the pin in the plane of a member 6|, which latter as shown in Fig. 1 has five teeth 63, will successively engage those teeth, and when it engages them will push the member 6| downward, as viewed in Fig. 1, to contact with the switch arm I1 and move it into contact with the switch arm I9, the member Bl, as hereinafter will be more fully explained, moving away from the switch arm 11 to cause the switch to open each time the pin enters the recesses between the teeth. Thus in this instance the bell 13 will be caused totap off five strokes. By placing three members 6| one above the other each in the plane of one of thepins 55, 51, 53 respectively, as shown by Fig. 4, and providing each member 6| so placed with a different number "the shaft 53 will be rotated at a slow speed say, for example, three or four revolutions per min- 'allel to the motor switch 65, 61.

49, is shown as controlled by a switch having the cooperating spring contact arms 65 and 61 which, in a manner hereinafter more fully explained, are caused to be closed' when any of the devices I5 cause a plurality of the member's 6I to be arranged in juxtaposition to the rotary member 49 for operating the bell. As shown in Fig. 1, one side of the motor is connected to one terminal of the battery 2| by the lead 31, while the other side of the motor is connected by the lead 69 to the switch arm 65, thecooperating switch arm 61 being connected by the lead 21 'to the opposite terminal of the battery. Hence when the switch afforded by the arms 65 and 61 is closed,'the motor will be placed in operation to rotate the member 49 and cause the bell I3 to sound the alarm.

With the arrangement just described, when the switch 65, 61 is opened by moving the members 6| out of juxtaposition to the rotary member 49, for causing a secession of the sounding of the alarm, the motor would stop operating in the'absence of something to prevent it. For the "purpose of causing the motor, when the motor switch 65, 61 is opened, to continue to operate until the member 49 places the teeth 55, 51, 59 in predetermined positions relative to that switch,

the shaft 53, as shown by Fig. 1, carries a rotary disk H of conductive material having at its periphery an insert 13 of insulating material, a

'brush 15 cooperating with the periphery of the disk and its insert and being connected by the lead 11 to the lead 21, which latter leads from one terminal of the battery to the switch arm 61 of the motor switch. As schematically illustrat- 'ed inFig. 1, the'hub portion 19 of the disk H is contacted by a brushBI which is'connected by a lead 83 to the lead 69 connecting one terminal of the motor to the other spring arm 65 of the motor switch. It will be noted that with this arrangement the disk H is placed in par- Hence if the motor switch is opened when the brush 15 is off the non-conductive insert 13 the motor will continue to operate until the brush 15 contacts with the insert 13, and this will cause the motor to stop when the rotary member 49 is in a prede- I termined position.

Referring particularly to Figs. 2 to 6 of the drawings, the motor 5|, as shown, is mounted on the panel II, the motor driving the vertical shaft 53, above referred to, through suitable reduction gearing, not illustrated, contained in a casing 85 carried by the motor casing, so that ute. This shaft 53, as heretofore explained, carries the rotary metallic disk 1I having the insert 13 of non-conductive material, the disk being "integrally-formed with a hub portion 81 secured to the shaft 53 by one or more set screws 89. The

brush 15 heretofore referred to is carried by a metallic arm 9I supported by the panel II in '75 insulated relation thereto, the end of which arm being alike.

two switches just referred to.

latter in practice is in electrical communication with the gear casing 85. Therefore in practice this circumstance may be taken advantage of "by insulating the motor casing from the panel and by grounding to this casing that terminal of the motor to which the lead 69 of Fig. 1 is connected; In other words, the brush 8|, shown schematically in Fig. 1 for convenience in illustration, may be entirely omitted by this expedient.

As illustrated in Fig. 4, the upper end of the shaft 53 is reduced in diameter at 91 to form an annular shoulder 99. This reduced portion of the shaft 53 receives the hub IOI of the rotary member49, the hub at its lower end resting upon the shoulder 99 and being secured to the shaft in adjusted rotative positions relative thereto by means of anut I03 screw-threaded on the end of the shaft. As shown, the skirt I05 of the rotary member 49 is provided with the projecting pins 55, 51 and 59 heretofore referred to, the pins being spaced circumferentially of the rotary member and each pin being in a different horizontal plane from the other.

As illustrated, the brush holding arm 9| has slidably and rotatably mounted thereon a block I01 of insulating material which is fixedly secured in adjusted positions to the arm by a set screw I119. This block carries the two switches formed by the pairs of contact arms 65, 61 and I1, 19 respectively. The construction of these switches is best illustrated in Fig. 4, both switches As shown, each switch comprises a pair of base portions III and H3 insulated from each other and to which the leads may be connected. The spring arm 61 and like spring arm I9 each comprise an elongated flexible metallic member carried at its lower end by the upper end of the base portion III. The arm 65 and like arm I1 each comprise an upper rigid metallic part connected to the base portion II3 by a flexible metallic spring II 5 which normally tends to hold the switch in open position.

As indicated in Fig. 4, the members BI hereinbefore referred to are dropped in difierent combinations into the space between the rotary member 49 and the upper rigid portions of the The upper rigid portion of the switch 65, 61 for controlling the motor carries a projecting portion I I1 of insulating material, so shaped that when three members 6I are piled one on the other on the upper surface of the block I01 the upper member SI of the pile will contact with the projection II1. Dropping the upper member 6I on the pile pushes the member II 1 to the right, as viewed in Fig. 4, and holds the switch 65, 61 permanently in closed position to energize the motor 5I for causing the member 49 to rotate, the latter continuing to rotate until the upper member 6| is moved from the space between the rotary member and projection II1 to permit the motor switch 65, 61 to open and subsequently until the brush 15 rides on the insert of insulating material on the member 11, as has hereinbefore been explained.

As illustrated, the upper portion 65 of the switch I1, I9 for sounding the bell I3 carries a lateral projection II9, of insulating material,

which is shaped to becontacted by each ofthe members 6| when they are moved to the right, as viewed in Fig. 4. As the member 49 rotates, the pins 59, 51, 55 successively engage the teeth of the respective members 6|, and, as each pin rides over the teeth of one of the members 6|,that member is moved successively to' contact the member I|9 to move the latter and cause it successively to open and close the switch I1, I9. Fig. illustrates the position of parts when the switch I1, I9 for operating the bell is in closed position. It will be noted that here. the pin 59 is in contact with the apex of one of the teeth 63 on the upper member 6|,and has pushed that member to the right to contact-with the projection IIS on the switch arm I1 to move that arm into contact with the arm. I9. When the pin moves farther in its travel it will enter the adjacent recess between the teeth 63, and. the upper member 6| will then, through a spring action hereinafter explained, which urges it'to the left as viewed in Fig. 5, move to the left out of contact with the projection I I9 and permit the switch I1, I9 to open. When the upper member 6| is moved to the right, as viewed in Figs. 4 and 5,t,oclose the switch I1, I9 the projection 1 carried by the switch arm 65 of the motor switch also moves to the right, this movement being permitted by the flexibility of the spring arm 61, which arm will follow the motion of the arm 65 and thus keep the switch 65, 61 closed and cause the motor to continue to rotate.

In this way as the pins successively ride over the teeth of the members 6| a number consisting of three digits (or less, if one or more of the members 6| is left blank in respect to teeth 63) is tapped by the bell I3. The value of each digit depends upon the number of teeth on the member 6|, and the value of the number tapped by the 40 bell depends upon the order in which the members 6| are placed on top of the block I01. As

illustrated, the parts are arranged for piling three members 6| on top of the block I61, but it will be understood that a greater orlesser number of 45 these may be piled there provided the projection I I1 for closing the motor switch is operated by the last member 6| placed on the pile and the projection H9 is arranged to be contacted by all the members that may be in the pile.

50 Referring particularly to Figs. 1, 2 and 5, it will be observed that six members 6| are herein illustrated, these members being provided with one, two, three, four, five and six teeth respectively. Each member 6| is carried at the end of a spring 55 arm I2I, the other end of which arm is rigidly carried by a block I23 swingingly mounted by a horizontal pivot I25 on a bearing block I21 carried by a bracket I29. Two such brackets are shown, arranged at opposite sides respectively of co the rotary member 49, the brackets being carried by the panel II. Extending upwardly from each block I23 is a rod I3I the upper end of which carries an armature I33 cooperating with the pole piece I35 of an electro-magnet I31. When the magnets I31 are energized to attract the armatures I33 the members 6| will be held in their full line positions illustrated by Figs. 2 and 3.

By deenergizing any of the magnets its associated member 6| will be permitted to drop into its dot-- ted line position, shown at the right of Fig. 3, between the projections H1 and H9 and rotary member 49 for operating the switches 65, 61 and I1, I9 respectively, as has been hereinbefore ex plained.

As illustrated, the arms |2| are so bent, and the blocks I21 are so positioned, that the membersfil will drop into proper juxtaposition with the rotary member 49-upon de-energization of the electromagnets, the mounting of the members 6| and their movement in this respect being similar to those of the keys of a typewriter. It will therefore be observed that by deenergizing three selected magnets in proper sequence, any combination comprising three difierent digits of the digits 1 to '6 inclusive may be caused to be tapped off by the bell I3. Obviously a greater or lesser number of members 6| could be provided, as hereinbefore. explained.

After an alarm has been sounded, and while it is being sounded, the members 6| may be again placed. in their elevated positions in any convenient manner, and will be held there by reason of current caused to flow through the windings of the magnets I31, which is the normal condition of the apparatus. bracket I29 is shown as provided with a shaft I39 which extends through the panel II to the back thereof. This shaft carries a number of fingers |4| positioned beneath the respective arms I2I.

Normally these fingers will be in their full line positions indicated in Fig. 3, but by turning the shafts I39 the fingers may be raised to. their dotted line positions shown at the left-hand side of that figure so as to engage the arms |2| and raise the members 6| and thus bring the armatures I33 into juxtaposition to the pole pieces of the magnets.

As illustrated in Figs. 2 and 6, each shaft I39 rigidly carries behind the panel II an arm I43, these arms extending in opposite directions relative to each other and being pivotally connected at their outer ends to a link I45, the link being urged by a spring I41, one end of which is connected to the link and the opposite end thereof to the panel, in such direction as will normally holdthe fingers I4 I in their lowermost positions. When the fingers are ,to be raised the link I may be moved by the operator to the right, as viewed in Fig. 6, to raise the fingers I4I.

It will be observed that as hereinbefore described the armatures I33 associated with the elements 6| of the selective switch device are held in their uppermost positions on account of current normally flowing through the windings of these magnets. However, as will be obvious to those skilledin the art, each armature may be held in upper position by means of a latch which disengages when the current fiows through the associated magnet winding, under which condition the magnets would be normally deenergized.

The windings of the magnets I31 for holding the elements 6| in their raised positions are indicated by the same reference character I31 in the schematic wiring diagram illustrated by Fig. 1. One terminal of these magnets as shown is connected by a common lead I 49 to the lead 31 from one terminal of the battery 2|. The other terminal ofeach of these magnets as shown is connected by a lead |5| to the movable contact I53 of a relay switch I55, the cooperating contacts I51 of all the relay switches being connected by a common lead I59 to the lead 21 which is connected to the opposite terminal of the battery 2|. When the switch 23 is closed, which is the normal condition of operation of the apparatus, the armatures |6| of all the relay switches will be drawn downward from the position of parts illustrated by Fig. 1 against the resistance of the tension springs I63 to close the switches I53, I51. When the current through the winding of any For raising the arms 6| each of these relay switches I55 is interrupted, the associated spring I63 will cause the switch I53, I51 to move into open position and therefore interrupt the flow of current through the associated magnet I31, thereby causing the selective switch element 6| controlled by that magnet to drop.

For energizing the windings of the relay switches I55 a tapped resistance, comprising the series connected resistance sections I65, is shown as connected across the opposite battery leads 21 and 31 through a resistance I61 and the winding of a relay I59 respectively, the resistance I61 preferably having the same value as the winding I69, and this value being low as, for example, in the order of 1 ohm so that approximately the entire voltage of the battery 2| will be impressed upon the tapped resistance.

The windings of the middle pair of relay switches I 55 as shown are bridged in series across the center resistance section I65, and the extreme right and left hand windings in series across the entire series of resistance sections, while the next to the left hand and next to the right hand windings as shown are bridged in series across the three center resistance sections.

Preferably, but not necessarily, each resistance section I55 has the same ohmic value, as likewise have all the windings I55. By inserting suitable resistances I1I in series with these windings the same potential drop across each winding may be had. Assume, for example, that each resistance section has an ohmic value of ohms and that there are employed five of these sections, and that there are impressed across the entire series of these resistances volts. In such case the drop across each of the two center windings will be 2 /2 volts. If each winding I55 has a resistance of, for example, 1500 ohms, by making the two resistances I1I associated with the right and left hand windings have a 'value of 6000 ohms, the

voltage drop across these last mentioned windings will be also 2 /2 volts because there are impressed upon this system of windings and resistances 25 volts. Similarly, if the two resistances associated with the next to the right and 'next to the left hand windings have a value of 3000 ohms, the drop across these windings will be 2 /2 volts because there are impressed upon the system including these windings and resistances 15 volts. As shown, a lead I13 at one end thereof is connected to the electrical center of three series of windings I bridged across taps on the resistance having the five sections I55. This connection of the three series of windings does not affect 55 the electrical conditions because the points of connection of the lead I13 thereto are at the same potential, namely, that potential which exists at the electrical center of the middle resistance section I55. In practice the wiring may be much simplified by causing theupper terminals of the winding of the relays I55, or the lower terminals of the resistances I'II when thelatter are employed, to be connected directly to the lead I13, instead of having the connections as'schematically illustrated in Fig. 1.

It will be observed that as heretofore described an even number of relays I55 is employed. If an odd number of relays is to be employed one of them may be connected in series with an equivalent resistance so as'in effect to provide an even number of relays so far as the resistances of the relays are concerned.

The lead I13 extends from wiring on the'panel II to all the devices I5 severally situated in dif- 75 ferent staterooms or.at different stations on the 1 the resistance I 8 I.

' ship. .Also leadingto these devices are a pair of leads I15 and I11 connected to opposite terminals of .the battery through the winding of the relay I69 and the resistance I61 respectively. It will be notedthat there are only three conductors leading from. the panel II to the devices I5. These conductors may exist as a three wire cable, across two wires of which the devices I5 are connected'in parallel, and'may be several hundred feet long so as to include a large number of state- 'rooms. In this way the complexity of wiring which has rendered .prior proposed systems of this sort impractical is entirely avoided.

As illustrated, each device I5 comprises a bimetallic.thermostatic'switch element I19 about which is wrapped a flexible tapped heating resistance I8I,. the resistance having six taps, herein numbered Ito 6, each corresponding to the tap of same number on the series of resistances I65.

As shown, the lei-metallic element of the upper device I5 in' Fig. 1 carries at its upper end in insulated' relation thereto a switch contact arm I83 connected to the tap I of the resistance, while the lower tap 6 of the resistance is connected by an appropriate lead and a normally closed manually operated switch I85'to the lead I15 from one side of the battery. Cooperating with the switch contact arm I83Z-is a flexible switch contact arm I81, which latter is connected to the lead I11 from the opposite terminal of the battery. If a fire occurs in proximity to this upper device I5 the thermostatic element will fiex to the left and move the switch contact arm I83 into contact with the flexible switch contact arm I81, and, the switch I 85 being normally closed, that will establish a circuit through the resistance I8I and further heat the bi-metallio element to cause it to flex farther to the left, the arm I81 bending during this continued flexure. At its upper end the bi-metallio arm carries at opposite sides thereof in insulated relation thereto a pair of contacts I89 and I9I which together with the upper end of the bi-metallic element are adapted to wipe over a cooperating switch arm I93 connected to the lead I13 leading to the electrical center of the system of windings of the relays I55 bridged across the series of resistance sections I65. It will be noted that continued flexure of the bi-metallic' elementwill move these three contacts to the left of the contact afforded by the switch arm- I93 so that each of the three contacts will be only momentarily connected to the lead I13. .This enables the system to be in condition for operation by successively actuated devices I5, it being observed that the members BI of the selective switch are dropped only when the lead I13 is connected to a tap on a resistance ISI, as will be hereinafter more fully explained. The manual switch I85, shown at the upper device I5 in Fig. 1',may be provided for all said devices and may be opened manually to disconnect the associated resistance I8I from the battery lead I15 under untoward conditions, say, if a fire occurring atthe station where the device I5 is situated should fuse its parts. Obviously, however, a fusible 'plug maybe substituted for the switch I85, and if desired the switch may be entirely omitted as indicated in the other devices The bi-metallic element I19 and the two contacts I89 and I 9I are adapted to be connected by different flexible leads'I95 to selected taps on For example, as shown in the upper device I5, the tap 2 is connected to the'contact I89,- the tap 4 to the 'bi metallic element I19, and the tap 3 to the contact I9I, for the purpose of causing the bell I3, when afire occurs at the station having the upper device I5, to tap oii the number 243. Byconnecting the leads I95 todifferent taps, as shown in the other devices I5 schematically illustrated, different numbers may be sounded when this device is actuated. Each device I5 employedpreferably has the taps difierently connected so that each device will cause a diiierent number to be tapped off by the bell.

It will be noted that the same voltage is impressed acrossthe terminals of the resistance I8I as across those of the series of resistance sections I65, and that when one of the contacts I89 and I9I and the contactafiorded by the upper end of the thermostatic element I19 contact with the switch arm I93 the potential of the tap on the resistance I8I to which the contact is connected will be impressed upon the lead I13. The resistance I83 divides the voltage in the same way as does the series of-resistances I65, as heretofore explained. Therefore, whenever a contact of the thermostatic element contacts with the switch element I93 there will be across the winding of oneof the relays I55 zero voltage or some predetermined voltage, depending upon the way the resistance I8I divides the voltage with relation to the way the series of resistances I65 divide it. For example, if the voltage is divided in the same way by these, and the contacts on the resistance I8I are connected as shown at the upper device I5 of Fig. 1, then when the contact I I39v contacts with the switch arm I9I the lead I13 will be connected to tap 2 on the resistance I 8|, which is at the same potential as the tap 2 on the series of resistances I65. Consequently the winding of the relay I55 connected to tap 2 on the series of resistances I65 will have impressed across it zero voltage, and that, relay thus will be deenergized to cause the associated switch I53, I51 to open and deenergize the winding of the associated magnet I31 to cause the selective switch element 6| controlled by that magnet to drop. Similarly, when the end of the thermostatic element contacts with the switch arm I93, the element 6| controlled by the relay I55 connected to the tap 4 on the series of resistances I65 will drop, while when the contact I9I contacts with the switch arm I93 the element 6| controlled by the relay I55 connected to the tap 3 will be caused to drop. a M

The, middle device I5, shown in Fig. 1, is exactly like that just described, except that, the resistance I8I is caused to be'connected across the leads I15 and I11 by means of a switch I91 held in open position by an explodable glass bulb I99. In case of fire the bulb will explode and permit the upper switch arm 20I of the switch I91 to move downward and contact with the lower contact shown as associated therewith.

The lower device I5, shown in Fig. l, in the above respects is exactly similar to the upper one, except that aseparate thermostatic switch is provided for connecting the, resistance I8I across the leads I13 and I11. This thermostatic switch comprises a bimetallic element 293. connected to one end of the resistance I8I and cooperates with the contact 295 connected to the battery lead I11. In case of firethe .element 293 will flex to close the switch, of which it constitutes one element, and thus cause the winding I8I to be energized. As will be obvious to those skilled in the art, both the switch 263 and the switch I91 heretofore described may be arranged in parallel so that each may control the energization of the resistance I8I in case of fire.

If desired, theresistance I8I can be caused to be energized by conditions other than those of heat as, for example, a switch controlled by fluid pressure in a sprinkler system may be employed, such a switch, for example, comprising a Bourdon tube 201 electrically connected to the upper end of the resistance I8I and having acontact 209 against which the tube moves when the pressure in the sprinkler system to which the Bourdon tube is connected drops to a predetermined value. As will be obvious, the fluid pres sure switch may be used alone or in conjunc tion with any of the heat sensitive switches hereinbefore mentioned for causing energization of the resistance I8I.

In operation, when the battery switch 23 is closed, the'tapped series of resistances. I65 will be connected across the battery terminals, the tap I being connected to the right hand battery terminal through the balancing resistance I61 and lead 21, and the tap 6 being connected to the left hand battery terminal through the lead I15, relay winding I69 and lead 31. As the relay windings I55 are connected in pairs across taps on the series of resistances I65, current flows through those windings and causes the armatures IfiI to be drawn down to close the switches I53, I51. When these switches are closed each of the windings I31 is placed in circuit across the battery because its upper terminal is connected to a lead I49 connected to the left hand battery lead 31 and its lower terminal is connected to the associated switch arm I53, which latter under these conditions contacts with the switch contact I51 connected to a lead I59 connected to the right hand battery lead 21. The energization of the windings I31 in this manner causes the spring arms I2I to be held intheir raised positions when moved to the same, in which positions each will stay until its associated winding is deenergized to permit the spring arm to drop as hereinbefore explained.

When a fire heats the upper thermostat shown at the right of Fig. 1, for example, flexure of the thermostatic element I19 closes the switch contacts I83, I81, and that, assuming the switch I95 isclosed, connects the associated resistance I8I across the battery in parallel with the series of resistances I65, because the lead I15, which is connected through the switch I85 to the lower terminal 6 of the resistance I8I, connects with the tap 6 of the series of resistances I65, while the lead I11, which is connected to the switch contact I81 and hence under these conditions to the tap I of the resistance I8I, connects with the tap I of the series of resistances I65. The flow of current through theresistance I8I causes continued flexure of the element I19 and causes the contact I89, the contactjafforded by the upper end of the element I19, and the contact I9I successively to, wipe over the contact portion of the switch arm I93 as hereinbefore explained.

As the switch arm I93 is connected tothe lead I13, one end of which lead is connected to the electrical mid point of each pair of windings I55 connected in series across taps on the series of resistances I55, and the resistance I8I is in parallel with that series of resistances and preferably divided the same way, there will be impressed on that mid point, when the contact 189, which is connected to the tap 2 on the resistance I8I, is wiping over the switch arm I93, a voltage which is the same as that of the tap 2 on the series of resistances I65. In consequence, under such conditions, there will be momentarily zero voltage across that relay winding I55 which is connected to the tap 2 of the series of resistances I65 when the contact I89 is wiping across the contact portion of the switch arm I9I and that relay winding will momentarily be' deenergized to cause the associated switch I53, I51 to open momentarily so as to cause momentary deenergization of the associated winding I31 controlled by that switch. When the winding I31 is deenergized the spring arm I2I controlled by it'is caused to drop. Similarly, the switches. I53, I51, controlled by the windings I55 connected to the taps 6 and 3 of the series of resistances I65, are caused momentarily to open as the upper end of the thermostatic element I19 and the contact I9I, respectively, successively wipe over the contact portion of the switch arm IIiI. This will set the alarm to tap 01f the number 263 in this example when the motor 5| is set in operation, because the members 6| having 26 and 3 teeth 63 are placed in the order mentioned in position to operate the alarm controlling circuit.

The circuit heretofore described lends itself admirably to supervision required by the fire underwriters rules. For example, the remote end of the two leads I15 and I11 may be bridged by a resistance ZII of high value, which will cause a feeble current to flow through those leads at all times and hence through the winding of the relay I69. Should either of these leads be broken, or should the battery 2| become weak, or the normally closed manually operated switch 23 be opened, the circuit through the relay I69 will be interrupted or fall to such a low value as to permit the tension spring 2I3 acting upon'the armature 2| 5 of the relay I69 .to raise that armature and close the normally open switch 2I1. Closure of this switch will establish a circuit through the continuously ringing bell 2I9 and battery 22I so as to sound an alarm.

This bell 2I9 may also be sounded if any of the leads I13, I15 and I11 leading'tothe thermostatic or other devices I5 become grounded. To this end the mid point of the battery 2| may be grounded as indicated at 223, as likewise may be the lead 225 running to the lower terminal of the winding 221 of a relay switch 229, the other terminal of this winding'being connected to the mid point on the series of resistances I65 so that normally no current flows through the winding. When an accidentalground occurs in any of the leads I13, I15 and H1 a circuit will thus be established throughthe winding 221 and cause thenormally open. switch 229 to close against the resistance of the spring 23I, which switch when closed establishes a circuit through the battery HI and bell 2I9.

'Itwill beunderstoodthat wide, deviations may be made from the forms of the invention herein described without departing from the spirit of the invention.

I claim:

1. In a signaling system, a-plurality of potentiometer devices at difierentstations responsive to conditions thereat to be signaled, a central station, an indicating code signal device at said central station, conductors common to all of said plurality of potentiometer devices and the central station, means at each potentiometer device actuated by the condition to be signaled for successively contacting selected points of the potentiometer to a certain one of said conductors, and means at the central station responsive respectively to the points of the potentiometer which are contacted for setting up respective code indicia of said signal device.

2. In a signaling system, a plurality of potentiometer devices at different stations responsive to conditions thereat to be signaled, a central station, an indicating code signal device at said central station, conductors common to all of said plurality of potentiometer devices and the central station, means at each potentiometer device actuated by the condition to be signaled for successively contacting selected points of the potentiometer to a certain one of said conductors, means at the central station responsive respectively to the points of the potentiometer which are contacted for settingup respective code indicia of said signal device, and means at the central station operating automatically upon the setting up of said code indicia for repeatedly indicating the code indicia set up.

'3. In a signaling system, a plurality of potentiometer devices at different stations responsive to conditions thereat to be signaled, a central station, an indicating code signal device at said central station, conductors common to all of said plurality of potentiometer devices and the central station, voltage divider means, means including a pair of said conductors and a switch at each of said first mentioned stations responsive to the condition thereat to be signaled for connecting the potentiometer at the station in parallel with a source of electromotive force and said voltage divider means, means at each potentiometer device, actuated by the condition thereat to be signaled, for successively connecting selected points of the potentiometer to another of said conductors, means responsive to a predetermined difference between potentials established by said'voltage divider means and those impressed on said last mentioned conductor by the points of the potentiometer successively connected thereto for successively setting up respective code indicia of said signal device.

4. A signaling apparatus comprising a plurality of devices at different stations responsive to the conditions to be signaled, a central station, three conductors common to all said devices and central station, a pair of said conductors being connected to the opposite terminals of a source of electromotive force, each device comprising a tapped resistance and means responsive to the condition thereat to be signaled for bridging said resistance across said pair of conductors and for successively connecting selected taps from said resistance to the third conductor, a. further tapped resistance bridged across said pair of conductors, means at the central station for setting up codev indicia comprising aplurality of electrically operated code indicia controlling devices severally bridged between different taps of said further resistance and third conductor, each code indicia controlling device being responsive to a potential established across it by the connection of said third conductor to a predetermined tap of each first mentioned resistance.

5. A fire alarm system comprising a plurality of heat responsive devices at different stations, a central station, three conductors common to all said devices and central station, a pair of said conductors being connected to the oppo-- site terminals of a source of electromotive force,

each device comprising a tapped resistance and means responsive to heat for bridging said resistance across said pair of conductors and for successively connecting selected taps from said resistance to the third conductor, a further tapped resistance bridged across said pair of conductors, means at the central station for setting up code indicia comprising a plurality of electrically operated code indicia controlling devices severally bridged between different taps of said further resistance and third conductor, each code indicia controlling device being responsive to a potential established across it by the connection of said third conductor to a predetermined tap of each first mentioned resistance.

6. In a signaling system, a central station, a plurality of devices at different stations each having movable means actuated in response to the condition to be signaled, a tapped resistance associated with each of said devices, a source of electromotive force, switch means operated by said movable means of each of said devices for bridging said resistance associated withthe device across said source of electromotive 'force and for successively connecting selected taps from said resistance to a conductor common to all of said plurality of devices and the central station, a further tapped resistance bridged across said source of electromotive force, and means at the central station for setting up code indicia comprising a plurality of electrically 0perated code indicia controlling devices severally bridged between said conductor and difierent taps on said further resistance.

7. In a signaling system, a central station, a plurality of devices at different stations each having movable means actuated in response to the condition to be signaled, a tapped resistance associated with each of said devices, a source of electromotive force, switch means operated by said movable means of each of said devices for bridging said resistance associated with the device across said source of electromotive force, means operated in response to the heat .generated by said resistance for successively connecting selected taps from said resistance to a conductor common to all of said plurality of devices and the central station, a further tapped resistance bridged across said source of electromotive force, and means at the central station for setting up code indicia comprising a plurality of electrically operated code indicia controlling devices severally bridged between said conductor and different taps on said further resistances.

8. In a fire alarm system, a central station, a plurality of heat responsive means at different stations, a tapped resistance associated with each of said means, each resistance being tapped to divide a voltage impressed thereon in the same way, a source of electromotive force, said means when responding to heat operating to bridge said resistance across said source of electromotive force, contact means operated by said heat responsive means for successively connecting a plurality of selected taps from said resistance to a conductor common to all of said plurality of heat responsive means and the central station, a further tapped resistance bridged across said source of electromotive force, which resistance is tapped to divide the voltage of said source of electromotive force in substantially the same way as the first mentioned tapped resistances, and means at the central station for setting up code indicia comprising a plurality of electrically operated code indicia controlling devices severally bridged between said conductor and different taps on said further resistance.

9. In a fire alarm system, a central station, a plurality of heat responsive means at different stations, a tapped resistance associated with each of said means, each resistance being tapped to divide a voltage impressed thereon in the same way, a source of electromotive force, said means when responding to heat operating to bridge said resistance across said source of electromotive force, contact means operated in response to the current flowing through said resistance for successively connecting a plurality of selected taps from said resistance to a conductor common to all of said plurality of heat responsive means and the central station, a further tapped resistance bridged across said source of electromotive force, which resistance is tapped to divide the voltage of said source of electromotive force in substantially the same way as the first mentioned tapped resistances, and means at the central station for setting up code indicia comprising a plurality of electrically operated code indicia controlling devices severally bridged between said conductor and different taps on said further resistance. 7

10. In a fire alarm system, a central station, a plurality of devices at different stations each having a like tapped resistance and thermostatic means for bridging said resistance across a source of electromotive force and for successively connecting different selected taps from said resistance to a conductor, said conductor and a pair of other conductors, the latter leading from the terminals of said source of electromotive force and adapted to have the several resistances of said dew'ces so bridged across them, being common to all of said plurality of devices and the central station; a further tapped resistance bridged across said pair of conductors, means at the central station for setting up code indicia comprising a plurality of electrically operated code indicia controlling devices severally bridged across said conductor and different taps on said further resistance, each tap of the first mentioned resistance when the latter is in circuit having a definite voltage relation to a tap on said further resistance, and said electrically operated code indicia controlling devices being severally operated when the voltage across them is substantially such definite voltage relation established by the tap on said first mentioned resistance connected to said conductor.

11. A signaling apparatus comprising a plurality of devices at different stations responsive to the conditions to be'signaled, a central station, three conductors common to all of said plurality of devices and the central station, a pair of said conductors being connected to the opposite terminals of a source of electromotive force, each device comprising a tapped resistance and means for bridging said resistance across said pair of conductors and for successively connecting taps from said resistance to the third conductor, a further tapped resistance bridged across said pair of conductors, means at the central station for setting up code indicia comprising a plurality of electrically operated code indicia controlling devices severally bridged between different taps of said further resistance and third conductor, said code indicia controlling devices being each responsive to a definite potential established across it by the connection of said third conductor to a definite tap of each of the first mentioned resistances, and means operating automatically upon setting up of the code indicia by said controlling devices for causing the code indicia to be successively indicated.

12. In a signaling system, a plurality of devices at difierent stations responsive to the condition thereat to be signaled, a central station, a make and break switch at the central station, a plurality of groups of detents adapted to be set up in different combinations, a movable part adapted to Wipe over said detents for operating said make and break switch, electric means at the central station adapted to be operated by each of said devices for setting up said groups of detents in different combinations depending upon the one of said devices which responds to said condition, a code signaling device at the central station controlled by said switch, a motor for operating said movable part, and means automatically operated upon the setting up of said groups of detents in any one of said combinations for causing said motor to wipe said movable part over said detents.

13. In a signaling system, a plurality of devicw at different stations responsive to the conditions thereat to be signaled, a central station, conductors common to all of said plurality of devices and the central station, all said devices having means for causing selected'voltages to be impressed successively on a certain one ofsaid conductors when said device responds to the condition thereat to be signaled, a code indicia signal device at the central station, and means responsive respectively to the impression of said voltages on said conductor for setting up respective code indicia of said signal device.

14. In a signaling system, a plurality of devices at different stations responsive to the conditions thereat to be signaled, a central station, conductors common to all of said plurality of devices and the central station, all said devices having means for causing selected Voltages to be impressed successively on a certain one of said conductors when said device responds to the condition thereat to be signaled, a code indicia signal device at the central station, means responsive respectively to the impression of said voltages on said conductor for setting up respective code indicia of said signal device, and means operating automatically upon the setting up of the code indicia for successively repeatedly indicating saidcode indicia set up.

15. In a signaling system, a plurality of potentiometer devices at different stations, a central station, three conductors common to all of said plurality of potentiometers and the central station, a pair of which conductors is adapted to energize the potentiometers, means at all of said potentiometers for selectively connecting any one of them in circuit with said pair of conductors and for successively contacting selected points of the potentiometer to the third conductor, a code indicating signal device at the central station, and means responsive respectively to the points of the potentiometer which are contacted for setting up respective code indicia of said signal device.

HAROLD J. GRAHAM. 

